[Construction of a Nomogram model of C5 nerve root palsy following posterior approach cervical single-door enlargement kyphoplasty].

Abstract

Objective: To analyze the factors influencing the occurrence of C5 nerve root palsy after posterior approach cervical single-door enlargement kyphoplasty and construct a Nomogram-related prediction model.

Methods: A total of 255 patients with cervical spondylotic myelopathy who underwent posterior cervical single-door laminoplasty between May 2019 and February 2023 were selected as the research subjects. They were divided into the occurrence group (45 patients) and the non-occurrence group (210 patients) based on whether C₅ nerve root palsy occurred after the operation. The general data of patients in the two groups were compared. The predictive value of statistically significant continuous variables was analyzed using receiver operating characteristic (ROC) curve analysis. The factors influencing patients' postoperative C₅ nerve root palsy were analyzed using Logistic regression analysis. And the clinical efficacy of Nomogram model was assessed using decision curve analysis.

Results: Compared with the non-occurrence group, the patients in the occurrence group had a shorter disease duration, higher preoperative cervical curvature and spinal cord posterior displacement distance, and higher percentage of positive pathological reflexes, foraminal stenosis, and ossification of the posterior longitudinal ligament.The difference was statistically significant P<0.05. The area under the curve (AUC) for cervical curvature and posterior displacement of the spinal cord prior to surgery were 0.699 and 0.697, respectively. The optimal cutoff values were determined to be 21° and 3 mm, with statistically significant differences (P<0.05). Logistic regression analysis showed that abnormal electromyography OR=6.693, 95%CI(2.754, 16.264), P<0.001;preoperative cervical curvature OR=2.254, 95%CI(1.215, 2.920), P=0.003;foraminal stenosis OR=3.049, 95%CI(1.234, 7.530), P=0.016;ossification of the posterior longitudinal ligament OR=2.646, 95% CI(1.015, 6.899), P=0.047;and the distance of spinal cord posterior displacement OR=0.298, 95% CI(0.173, 0.513), P<0.001;which were all related factors influencing postoperative C₅ nerve root palsy in patients with this disease. The C-index of the Nomogram model for predicting the risk of postoperative C₅ nerve root palsy in patients was 0.861, with a 95% confidence interval of (0.795, 0.927). The risk threshold of this model was determined to be greater than 0.17.

Conclusion: Abnormal electromyography, preoperative cervical curvature, intervertebral foramen stenosis, ossification of the posterior longitudinal ligament, and the degree of posterior displacement of the spinal cord are all significant contributing factors to C₅ nerve root palsy following posterior cervical single-door laminoplasty. A prediction model developed based on these factors demonstrates enhanced accuracy and substantial clinical application value.